Manufacture of threads of textile material



June 26, 1934.

Filed April 11. 1930 2 Sheets-Sheet l FIGL- Patented June 26, 1934MANUFACTURE OF THREADS OF TEXTILE MATERIAL Jean Etienne CharlesBongrand, Paris, and Lon Sylvain Max Lejeune, Wasquehal, FranceApplication April 11, 1930, Serial No. 443,470 In France November 8,1929 6 Claims. (01. 111-2) The present invention has for its object animproved process for the manufacture of threads of textile material,resulting in threads in which every textile fibre is entirely envelopedand in part penetrated, those at the center of the thread as well asthose at the periphery thereof, by an elastic substance such as naturalor artificial aqueous dispersion (latex) of rubber or balata or gutta.

It has already been proposed to impregnate textile threads by means of asolution of rubber or of latex, but the means proposed for carrying outsuch an impregnation have not been sufficient to impregnate rightthrough the core of the thread and to envelop or penetrate theindividual fibers of the thread.

By means of this invention a complete penetration right through the coreof the thread or yarn is accomplished, and the process '"consists insubjecting the fibrous mass or roving, before twisting or cording, tocontact in a closed container with the treating'dispersion (latex) underthe action of a fluid under pressure. The

percentage of the treating material absorbed by 2 the fibrous mass orroving depends upon the time during which the contact is eflected andupon the degree of the pressure exerted. The degree of pressure and theduration of treatment required to effect the complete interpenetrationand impregnation and intimate envelopment of the elementary fibers willdepend somewhat upon the character of the particular fibrous massundergoing treatment; but those operating conditions are readilydetermined by trial. After having been penetrated with latex the fibersare twisted and corded together and then dried.

In the threads or yarns obtained according to our invention, theelementary fibres are connect- 40 ed to their neighbours by theimpregnating material, for instance rubber, which forms an elastic bondbetween them having remarkable mechanical properties, so that for oneand the same quality of fibres, a smaller twist gives the a samestrength, and with the same twist and even with a smaller twist, shorterfibres may be used.

Even in the case of twisted or cabled threads, according to theinvention the elementary fibres are deeply enveloped and impregnated. Insuch threads, the complete coating with rubber-of each of the elementsisolates or separates each of the elements from the others, which isvery advantageous for certain applications (for instance threads forpneumatic tyres).

The threads or yarns obtained by the present tion of the bath.

invention differ from the known threads coated outside with a'rubbersolution or relatively incompletely coated with latex and used forforming the thread framework in outer covers of pneumatic tyres, calledcord, by the fact that the rubber impregnates them deeply in orderclosely to connect the fibres to one another and then the thread or yarnis coated, whilst in the case of the outside rubber application by theusual processes, not only are the elements constituting the cord andformed by threads stranded or corded together, not impregnated to theircentre, but are not even isolated by the rubber from one another.

According to the invention each thread is impregnated and coated withlatex before twisting and cording and the threads are twisted and cordedtogether before drying.

We have found that when the twisting of the impregnated roving is donebefore drying, the impregnation of the individual fibers is morethorough and the adhesion of the fibers one to another is moretenacious; the effect of the twist upon the yet moist fibers being torender the penetration thereof by the rubber more complete and the unionof the'latter with the individual fibers more perfect.

The threads according to the invention difier also by the fact of theirimpregnation and of the nature of the impregnating and coveringmaterialfrom threads finished with starch in solution or with otheradhesives. Y

The treatment under pressure may be, if desired, completed by asuperficial treatment at atmospheric pressure in winding off the threadsin a bath of anelastic substance, for instance latex, concentrated ornot, the threads being sub jected to the action of brushes before andalso after immersion in said bath.

'Ihe accompanying drawings show diagrammatically by way of example anapparatus suitable for carrying the present process into practicaleffect.

Fig. 1 shows an apparatus for the treatment under the-action of a fluidunder pressure, a vacuum being used for accelerating the c'ircula- Fig.2 is a similar view, partly in section of the apparatus for thecomplementary treatment.

Fig. 3 is a plan of the same and Fig. 4 an end elevation.

The apparatus shown in Fig. 1 is constituted by a container :1 withautoclave closing device for receiving the fibrous mass to be treatedand by another container 1) for the impregnating liquid; 1

twisted is a filling vat and h a cock. The fibrous strands insubstantially untwisted condition are preferably placed on bobbins dwith flexible and perforated spindles e affording passage to the liquid.The said bobbins are threaded on a perforated tube f and held closetogether by a clamping device such as g. If the fibrous mass is inhanks, these hanks are placed in packets and arranged round the centraltube ,f.

The containers a and b are connected by the pipe is and cock 7' on theone hand and by the pipe :1: and cock t on the other hand.

In the container b opens a compressed gas pipe 1' which may be closed bythe cock 8 and the same pipe opens into the container a through the piper and the cock q. A vacuum pipe 0 opens into the container b (cock u)and into the container a (cock p) the vacuum being used for acceleratingthe circulation of the liquid.

The operation is as follows:

The apparatus being first completely empty, the bobbins d are placed inthe container a; the latter is closed by a number of tightening screws 0and all the cocks are then closed; the container b is filled, throughthe intermediary of the filling vat 1', with the impregnatingdispersion, the cocks h and '0 (air escape) being opened; when thecontainer b is filled, the cooks h and v are closed and the cock 1)opened so that a certain vacuum is created in the container a. The cocksn and 7 are then opened to cause the passage of the liquid from b to a,and at the same time the compressed gas cock 8 is opened; when theliquid has reached a determined level the cock n is closed. The threadsare now in contact with the impregnating material under a determinedpressure of the compressed gas (nitrogen for instance). After a suitabletime of contact the cocks sand 7' are closed and the cock 2; opened forthe air escape. When the pressure has fallen to zero in the container b,the cock u is opened to create a certain vacuum in the said containerand then the cock t is opened to allow the liquid which is in a toreturn into b. On the other hand the cock q is opened'in order toaccelerate, by the pressure, the back flow of the liquid from a to b.

The operations as described may be repeated several times if desired.The percentage of the impregnating liquid absorbed by the thread dependsupon the time of the contact under pressure and upon the degree of thepressure. The bobbins are then unwound by hand and dried, preferably invacuum in order to hasten the drying and to enable the work to be doneat higher temperatures.

To the aqueous dispersion we may add mineral or organic substances.These fillers and the like must not produce coagulation, but must be ina colloidal state or as much dispersed as possible. Any suitable agent(such as ammonia) is added for avoiding premature coagulation.

If necessary, to the aqueous dispersion may be added sulphur,polysulphide and also a vulcanization accelerator.

When latex is used as the impregnating substance in carrying out thepresent process, special advantages are obtained, particularly in thatthe rubber adheres more closely, it is much more tenacious than therubber obtained from an evaporated solution. The rubber coming fromlatex is, as is well known, in an undepolymerized condition, and to thisit seems are due the special properties mentioned. Under the action ofheat, the rubber of the latex coagulates. The coagulation of the latexmay be rendered more complete by the action :of dilute acetic. acid, forinstance.

The yarns impregnated with latex-of rubber or balata or gutta in themanner described, or may be then assembled into a twisted thread by theordinary spinning processes, before the coagulation and drying. Thesetwisted threads are then stranded or corded if necessary, before thecoagulation and drying. They may be twisted or corded after drying, butthe result is not so good.

The threads thus obtained may be utilized in the rubber industry asinsertion textiles in the form of web cord for pneumatic tyres or ofcords for hose-pipes or in the form of fabrics. To that end, theimpregnation rubber may be given suitable fillers and the like andvulcanization elements.

These threads unite much better with the mass of rubber of themanufactured article than the ordinary threads coated with rubber on thesurface.

The threads according to the invention may be woven, the fabric beingthereupon vulcanized either hot or cold by the usual means. Thesefabrics formed of absolutely impermeable threads, may themselves be alsowaterproof whilst remaining permeable to the air. Such fabrics may alsobe obtained by the weaving of previously vulcanized threads.

As stated in the foregoing, the deep impregnation with the assistance ofpressure, may be carried out with fibrous strands previously wound onperforated warp beams (for obtaining for instance the web cord used inthe manufacture of pneumatic tyres) or also of ribbons and the like. Inthis case the perforated warp beams are threaded on perforated tubessimilar to the tubesf of Figure l and placed into the autoclavecontainer a. The liquid latex placed under pressure passes through thewarp beams from the inside outwards, and the resistance opposed to thepassage forces the liquid to penetrate completely into the threads andenvelop the individual fibers. The proceeding is similar also forribbons or tapes. The warp beams are then unwound and submit- 120 ted todrying which brings about the coagulation, and if necessary tovulcanization. In that way are prepared directly web cords for pneumatictyre industry, waterproof fabrics for clothing, insulating tapes forelectricity for instance.

The threads or yarns according to the present invention after they havebeen vulcanized either hot or cold, have a different appearance and feelfrom those of other textiles. They are impermeable and do not putrefyand possess high dielectric properties. For these various reasons, theyare utilized for the weaving for instance of fabrics for umbrellas, forhosiery, trimmings; lace making and in the electric industry forbraiding or covering of electric wires. 135

For these applications it may be advisable to' proceed with a surfacecoating of rubber after the depth impregnation such as described. By

this operation the outside fiufi', for instance, may

be caused to completely disappear. For this rubber surface coatingconcentrated latex may be used, in place of latex.

This complementary treatment may be effected for'instance by means ofthe apparatus shown in Figs. 2 to 4. The strand 1 to be impregnated,coming from a bobbin 2, passes first between the bristles 3 of a brush 4secured to a support 5, then between the bristles 6 of a brush '7secured to a movable cover provided with a support 8 and a joint 9. Thestrand passes finally through the which is placed 1,964,658 bristles 10of a brush 11 also secured to the support and between the bristles 12 ofa brush 13 before being wound on the reel 14. The support 5 has a vat 15provided with a recess 16 into the complementary treating liquid. Thecover 8 is mounted on the support 5 by means of a hinge 1'7 and may beheld'against the said support by means of a closing device 18. Betweenthe brush and the brush 12, the strand passes through an eyelet 19having a reciprocating motion.

The cover 8 having been raised and the vat filled with latex orconcentrated latex 16, the strand is unwound from the bobbin 2 andcaused to pass through the bristles 3, 10 and 12 o! the brushes 4, 11and 13 and the end of the thread is attached to the reel 14. The cover 8is then turned down and locked by the device 18, with the result thatthe strand is caused to engage with the bristles 6 of the brush '1 andto be immersed in the vat 15. The reel 14 is then started, and

. the strand is unwound from the bobbin 2 in order tom drying andcoagulation,

to pass successively through the brushes 4, 6, 11 and 13, owing to whichit is superficially treated or coated by the liquid the excess of whichis removed and regulated by the brush 13, and through the bristles 12 inwhich the strand rubs not only longitudinally owing to its movement, butalso transversely owing to the reciprocating movement of the eyelet 19.

What we claim is:

1. A process for the treatment of textile fibers with an elasticsubstance consisting in placing the fibers in the condition of rovings,or bobbins in an air tight container in contact with an aqueousdispersion of rubber under the pressure of a gas, then unwinding theimpregnated fibers through a bath of latex removing the excess of the impregnating material, drying the thread and imparting to it an additionalsmoothing.

2. A process for the manufacture of twisted or corded threads in whichthe rovings are first impregnated with latex in a closed container undergaseous pressure, are then twisted or corded bethe cords being thencovered with an additional quantity of latex, then winding and unitingthe threads in web cords.

3. A process for the treatment of textile fibers with an elasticsubstance, consisting in placing the fibers, in the condition ofrovings, on bobbins in an airtight container in contact with an aqueousdispersion of rubber under the pressure of a gas until the fibers arepenetrated and impregnated with the rubber, then unwinding theimpregnated fibers through a bath of latex, and then drying the thread.

4. A process for the treatment of textile fibers with an elasticsubstance, consisting in placing the fibers, in the condition ofrovings, on bobbins in an air tight container in contact with an aqueousdispersion of rubber under the pressure of a gas until the fibers arepenetrated and impregnated with the rubber, then unwinding theimpregnated fibers through a bath of latex, drying the thread andimparting to it an additional smoothing.

5. A process for the treatment of textile fibers with an elasticsubstance, consisting in placing the fibers in the condition of rovingson bobbins in an air tight container in contact with an aqueousdispersion of rubber under the pressure of a gas, exerting successivelya vacuum on the aqueous dispersion of rubber and a pressure by a gasonto the said dispersion, then unwinding the impregnated fibers andsubjecting them to the action of a strong coagulating agent.

6. A process for the treatment of textile'fibers with an elasticsubstance, consisting in placing the fibers in the condition of rovingson bobbins in an air tight container in contact with an aqueousdispersion of rubber under the pressure of a gas, exerting successivelya vacuum on the aqueous dispersion of rubber and a pressure by a gasonto the said dispersion, then unwinding the impregnated fibers andsubjecting them to the action of acetic acid.

JEAN ETIENNE crrARLEs BONGRAND. LEON SYLVAIN MAX LEJEUN'E.

